[wighty]

Just opened up our storage jars of plain and self raising flour and noticed little brown things moving around on the top.  Disposed of and a packet of 'ready made' white sauce used instead.  I know we've talked about flour weevils before but this is the first time I've ever come across them.    Where do they come from.  My cupboards are clean and we use a lot of plain flour so it's not going to be that old.

[Aunt Sally]

Not your fault Wighty.  I keep my flour and sugar in air tight food containers.  That will stop them getting in.

https://www.ukflourmillers.org/psocids#:~:text=Psocids%20(or%20flour%20weevils)%20are,stored%20in%20air%2Dtight%20containers.

[mumofstig]

when I buy flour I keep the bags inside sealed zip-lock bags. That also seems to work.

[Subversive_plot]

What MoS just said (Zip-Lock bags, sealed) is what we mostly do, but also what Aunty said (Airtight containers) with some things. We also have miller moths, and ants that invade from outdoors.  They will exploit the tiniest crack or crevice.

Storage containers need to have a rubber seal around the lid or screw top.

Zip-lock bags need to be airtight as well, no pinholes or zippers that no longer seal.

[wighty]

Thank you for the link Auntie, which has made me feel happier today.  Flour in this house has always been kept in Tupperware containers that I brought a long time ago which were sold as 'dried goods' containers.  One of the things that we don't like about our house is there is very little ventilation in the kitchen.  The house is sold but we can't find another one we both like.  We like this side of the Island, but there's not much available at the moment.   Fortunately our purchaser can put the money from their sale in the Bank and sit on it and wait for us to find what we want.

[Hampshire Hog]

I have experienced this in the past. I have found weevils inside unopened bags of flour in the past.
One strategy is to freeze the bag of flour in a plastic bag and then return to room temperature when you need to use it. Obviously you then need to keep the flour at room temperature after that in closed container. Seems to have reduced the problem so far.